Archive: Mar 2009

  1. Women in Engineering

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    Women in the field of engineering have always been in the minority. Even at schools with the highest female enrollment rates, numbers rarely exceed 30%. And in the workplace, female engineers are vastly outnumbered as well.

    “The ranks of women engineers have grown from less than 2% of all engineers in the United States in 1978 to 9% of engineers today,” states a recent National Research Council study, Women Scientists and Engineers Employed in Industry: Why So Few? According to the study, working conditions for women in industry are perceived as being less favorable, thus resulting in fewer women in the field.

    For women to make their way in the field, the key is to seek mentorship and support. Check out IEEE Women in Engineering (www.ieee.org/web/membership/women/index.html) or Society of Women Engineers (http://societyofwomenengineers.swe.org).

    Engineering is a broad field that has enough work for all types of people. Here are a few examples of successful female engineers from Engineer Girl (www.engineergirl.com):

    • Ada Byron Lovelace helped invent a machine that would eventually lead to the modern computer. She also predicted the development of software and artificial intelligence years before they actually became reality. She even has a computer programming language named after her.
    • Grace Murray Hopper created the first computer compiler that allows programmers today to write their programs using English rather than machine language, making their jobs much easier.
    • Elsa Garmire advanced optical technology, making the commercial use of lasers possible. Thank her the next time you use a CD player or print something using a laser printer.
    • Stephanie Kwolek discovered a solvent that later became used in the production of Kevlar, the key component of bulletproof vests.
    • Mary Anderson invented the windshield wiper that is widely used in cars today.

    Read more about women in engineering at www.GraduatingEngineer.com.

  2. Ahead by a Nose

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    While general wisdom says that you look at the eyes first in order to recognize a face, University of California, San Diego computer scientists now report that you look at the nose first.

    The nose may be the where the information about the face is balanced in all directions, or the optimal viewing position for face recognition, the researchers from UC San Diego’s Jacobs School of Engineering propose in a paper recently published in the journal Psychological Science.

    The researchers showed that people first look just to the left of the center of the nose and then to the center of the nose when trying to determine if a face is one they have seen recently. These two visual “fixations” near the center of the nose are all you need in order to determine if a face is one that you have seen just a few minutes before. Looking at a third spot on the face does not improve face recognition, the cognitive scientists found.

    Understanding how the human brain recognizes faces may help cognitive scientists create more realistic models of the brain, models that could be used as tools to train or otherwise assist people with brain lesions or cognitive challenges, explains Janet Hsiao, the first author on the Psychological Science paper and a postdoctoral researcher in the computer science department at UC San Diego.

    “The nice thing about models like neural nets is that—unlike computer programs—you can lesion them and they still run, which means you can test them in ways you could never test a human brain,” says Garrison Cottrell, an author on the paper and a computer science professor at UC San Diego’s Jacobs School of Engineering. “Understanding how the brain works is the greatest mystery facing us in this century and that is just what we are trying to do,” states Cottrell, who directs the NSF-funded Temporal Dynamics of Learning Center (TDLC) at UC San Diego.

    In the experiments reported in Psychological Science, subjects were shown images of faces they had seen a few minutes prior and images of faces they had never seen. The subjects had to decide in a very short time whether they recognized each face or not. Meanwhile, the researchers used eye tracking technology to monitor where on each face the subjects looked—and how long their eyes stayed at each location.
    In particular, the researchers employed an innovative eye tracking approach that allowed them to control how many different places on the face subjects could “fix” their eyes before the image disappeared.

    When subjects were allowed to fix their eyes on two different face locations, they performed better on face recognition tasks than when they were given the same amount of time but could only look at one spot on the face. Allowing a third or fourth fixation did not improve performance.

    Cottrell explains, “The location of the second fixation, like the first, was almost always near the center of the nose. This means you are just shifting the face you are looking at on your retina a bit. This shift changes which neurons are firing in your retina and therefore changes the neurons in the cortex that the visual pattern goes to.”

    www.GraduatingEngineer.com

  3. Water Supplies Could be Strongly Affected by Climate Change

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    Ground WaterIt’s no simple matter to figure out how regional changes in precipitation, expected to result from global climate change, may affect water supplies. Now, a new analysis led by MIT researchers has found that the changes in groundwater may actually be much greater than the precipitation changes themselves.

    For example, in places where annual rainfall may increase by 20% as a result of climate change, the groundwater might increase as much as 40%. Conversely, the analysis showed in some cases just a 20% decrease in rainfall could lead to a 70% decrease in the recharging of local aquifers—a potentially devastating blow in semi-arid and arid regions.

    But the exact effects depend on a complex mix of factors, including soil type, vegetation, and the exact timing and duration of rainfall events, so detailed studies will be required for each local region in order to predict the possible range of outcomes.

    The research was conducted by Gene-Hua Crystal Ng, now a post-doctoral researcher in MIT’s Department of Civil and Environmental Engineering (CEE), along with King Bhumibol Professor Dennis McLaughlin and Bacardi Stockholm Water Foundations Professor Dara Entekhabi, both of CEE, and Bridget Scanlon, a senior researcher at the University of Texas.

    The analysis combines computer modeling and natural chloride tracer data to determine how precipitation, soil properties, and vegetation affect the transport of water from the surface to the aquifers below. This analysis focused on a specific semi-arid region near Lubbock, Texas, in the southern High Plains.

    Predictions of the kinds and magnitudes of precipitation changes that may occur as the planet warms are included in the reports by the Intergovernmental Panel on Climate Change (IPCC)and are expressed as ranges of possible outcomes. “Because there is so much uncertainty, we wanted to be able to bracket the expected impact on water supplies under the diverse climate projections,” Ng says.

    “What we found was very interesting,” Ng continues. “It looks like the changes in recharge could be even greater than the changes in climate. For a given percentage change in precipitation, we’re getting even greater changes in recharge rates.”

    The team presented the results as a range of probabilities, quantifying as much as possible “what we do and don’t know” about the future climate and land-surface conditions, Ng says. “For each prediction of climate change, we get a distribution of possible recharge values.”

    For more study results, go to http://web.mit.edu/newsoffice/2008/agu-groundwater-1218.html.

    Read more about civil engineering and climate change at www.GraduatingEngineer.com.